Martijn van Oosterhout <kleptog@svana.org> writes:
> Err, that means copy is just rewriting the executable code in the
> backend of the server, while it's running, which understandably
> crashes.
No, I don't think so. "cp -f" means "unlink the old file and create a
new one", as opposed to plain cp which would overwrite in place. Your
theory would explain an observation that plain cp causes a crash while
cp -f does not, but that's the exact opposite of Merlin's report.
The actual situation is that the mmap is referencing a file that's
disappeared from the directory structure (but still exists on disk,
as long as it's held open). dlsym seems unable to cope with that
case. I call that a bug --- it'd be OK for it to return a failure
indication, but not to SIGSEGV.
regards, tom lane